Comment API lines in older versions

If you downgrade a devbox it will fail with:

Error while loading /etc/koha/sites/kohadev/plack.psgi: Can't load application from file "/home/vagrant/kohaclone/api/v1/app.pl": Can't locate object method "cache_dir" via package "Swagger2::SchemaValidator" at /usr/share/perl5/Swagger2.pm line 41.